U.S. patent number 5,755,289 [Application Number 08/640,458] was granted by the patent office on 1998-05-26 for drilling rig elevator with replaceable clamping inserts and method for installation.
This patent grant is currently assigned to Tesco Corp. Invention is credited to Per G. Angman, Jens Lutzhoft, Hans-Jurgen Ulbrich.
United States Patent |
5,755,289 |
Angman , et al. |
May 26, 1998 |
Drilling rig elevator with replaceable clamping inserts and method
for installation
Abstract
An elevator mechanism for use on drilling rigs for hoisting and
lowering different sizes and types of pipe. At least two elevator
frame sections are interconnected in relative moveable relation for
movement between an open position for receiving a section of pipe
and a closed position clamping about the pipe. At least two pipe
clamping inserts being received in interengaged relation by
respective elevator frame sections in a manner resisting upward and
downward movement relative to the frame sections. The pipe clamping
inserts are mechanically interengaged with the elevator sections to
prevent inadvertent disassembly downward and are releaseably locked
to secure the inserts against rotation relative to the frame
sections. For assembly and disassembly of the inserts relative to
the frame sections, the inserts, when unlocked, are rotated for
engagement or separation of the mechanically interengaged
relation.
Inventors: |
Angman; Per G. (Alberta,
CA), Lutzhoft; Jens (Hamburg, DE), Ulbrich;
Hans-Jurgen (Hamburg, DE) |
Assignee: |
Tesco Corp (Calgary,
CA)
|
Family
ID: |
24568335 |
Appl.
No.: |
08/640,458 |
Filed: |
May 1, 1996 |
Current U.S.
Class: |
166/378;
166/77.51; 175/202 |
Current CPC
Class: |
E21B
19/06 (20130101) |
Current International
Class: |
E21B
19/00 (20060101); E21B 19/06 (20060101); E21B
019/06 () |
Field of
Search: |
;166/77.1,77.52,77.53,378 ;175/85,195,203 ;294/102.2,90 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Tsay; Frank
Attorney, Agent or Firm: Bush, Riddle, & Jackson,
L.L.P.
Claims
What is claimed is:
1. A method for connecting replaceable pipe clamping inserts in
pipe supporting assembly with a drilling rig elevator mechanism,
having elevator frame sections defining insert receptacles and
having replaceable pipe clamping inserts defining an external
geometry for mechanically engaged relation with respective elevator
frame sections, said insert receptacles defining at least one
arcuate internal groove and said pipe clamping inserts defining at
least one arcuate external locking flange; said method
comprising:
(a) moving said pipe clamping inserts into mechanically engaged
relation within said insert receptacles so as to support said pipe
clamping inserts against axial movement thereof in at least one
axial direction;
(b) locking said pipe clamping inserts against disassembly from
said mechanically engaged relation; and
(c) moving said pipe clamping inserts relative to said elevator
frame sections such that a mechanically engaged relation is
established between said arcuate internal groove and said arcuate
external locking flange for securing said pipe clamping inserts
against said axial movement relative to said elevator frame
sections.
2. An elevator mechanism for use on drilling rigs for hoisting and
lowering pipe, comprising:
(a) at least two elevator frame sections being interconnected in
relative moveable relation for movement between an open position to
permit assembly thereof about a section of pipe and a closed
position clamping about a section of pipe in preparation for
hoisting and lowering thereof; said elevator frame sections
defining insert receptacles having arcuate groove means;
(b) at least two pipe clamping inserts being received in said
insert receptacles in interengaged relation by respective elevator
frame sections and secured by said interengaged relation against
upward and downward axial movement relative to said elevator frame
sections; said inserts defining arcuate flange means engageable
within said arcuate groove means, said arcuate flange means
supporting said inserts against axial movement relative to said
elevator frame sections;
(c) means securing said pipe clamping inserts in mechanically
interengaged relation with respective elevator frame sections and
securing said clamping inserts against upward and downward axial
movement relative to said elevator frame sections; and
(d) means releasably locking said pipe clamping inserts in assembly
with said elevator frame sections.
3. The elevator mechanism of claim 2, wherein:
(a) said arcuate groove means defining a downwardly facing undercut
shoulder; and
(b) said arcuate flange means having an upwardly facing geometry
corresponding to the configuration of said undercut shoulder and
being disposed for upward force resisting engagement therewith.
4. The elevator mechanism of claim 3, wherein:
said arcuate groove means and said arcuate flange means being of
hook-like cross-sectional configuration.
5. The elevator mechanism of claim 2, wherein:
(a) said elevator frame sections each defining arcuate rims;
and
(b) said pipe clamping inserts defining arcuate retainer means
overlying said arcuate rims and restraining downward axial movement
of said pipe clamping inserts relative to said elevator frame
sections.
6. The elevator mechanism of claim 5, wherein:
(a) said arcuate rims projecting upwardly from respective elevator
frame sections; and
(b) said arcuate retainer means being outer peripheral flanges of
said pipe clamping inserts, said outer peripheral flanges defining
downwardly facing grooves receiving said arcuate rims therein.
7. An elevator mechanism for use on drilling rigs for hoisting and
lowering pipe, comprising:
(a) at least two elevator frame sections being interconnected in
relative moveable relation for movement between an open position to
permit assembly thereof about a section of pipe and a closed
position clamping about a section of pipe in preparation for
hoisting and lowering thereof;
(b) at least two pipe clamping inserts being retained in releasable
assembly by respective elevator frame sections and being of a
configuration for interfitting relation with a particular size and
type of pipe;
(c) said elevator frame sections each defining an insert receptacle
having internal arcuate groove means; and
(d) arcuate flange means being defined by said inserts and being
engageable within said arcuate groove means of respective insert
receptacles, said arcuate flange means supporting said inserts
against axial movement relative to said elevator frame
sections.
8. The elevator mechanism of claim 7, wherein:
(a) said arcuate groove means defining a downwardly facing undercut
shoulder; and
(b) said arcuate flange means having an upwardly facing geometry
corresponding to the configuration of said undercut shoulder and
being disposed for upward force resisting engagement therewith.
9. The elevator mechanism of claim 7, wherein:
said arcuate groove means and said arcuate flange means being of
hook-like cross-sectional configuration.
10. A method for connecting replaceable pipe clamping inserts in
pipe supporting assembly with a drilling rig elevator mechanism,
having elevator frame sections defining insert receptacles and
having replaceable pipe clamping inserts defining an external
geometry for mechanically engaged relation with respective elevator
frame sections, said insert receptacles defining at least one
arcuate internal groove and at least one arcuate rim, and said
clamping inserts defining arcuate ends, at least one arcuate
external locking flange, and at least one arcuate rim receptacle;
said method comprising:
(a) moving said pipe clamping inserts into mechanically engaged
relation within said insert receptacles so as to support said pipe
clamping inserts against axial movement thereof in at least one
axial direction;
(b) locking said pipe clamping inserts against disassembly from
said mechanically engaged relation; and
rotating each of said pipe clamping inserts into mechanically
engaged relation with its respective insert receptacle until said
arcuate external locking flange is disposed in fully engaged
relation within said arcuate internal groove and said arcuate rim
receptacle is disposed in fully engaged relation about said arcuate
rim and said pipe clamping inserts are in axially restrained
relation with said elevator frame sections in both upward and
downward axial directions.
11. A method for connecting replaceable pipe clamping inserts in
pipe supporting assembly with a drilling rig elevator mechanism,
having elevator frame sections defining insert receptacles and
having replaceable pipe clamping inserts defining an external
geometry for mechanically engaged relation with respective elevator
frame sections; comprising:
(a) moving said pipe clamping inserts into mechanically engaged
relation within said insert receptacles so as to support said pipe
clamping inserts against axial movement thereof in at least one
axial direction; said pipe clamping inserts defining at least one
external locking receptacle;
(b) locking said pipe clamping inserts against disassembly from
said mechanically engaged relation; and
(c) securing locking means to said elevator frame sections and in
rotation restraining engagement within said external locking
receptacle.
12. An elevator mechanism for use on drilling rigs for hoisting and
lowering pipe, comprising:
(a) at least two elevator frame sections being interconnected in
relative moveable relation for movement between an open position to
permit assembly thereof about a section of pipe and a closed
position clamping about a section of pipe in preparation for
hoisting and lowering thereof; said elevator frame sections
defining insert receptacles;
(b) at least two pipe clamping inserts being received in said
insert receptacles in interengaged relation by respective elevator
frame sections and secured by said interengaged relation against
upward and downward axial movement relative to said elevator frame
sections;
(c) means securing said pipe clamping inserts in mechanically
interengaged relation with respective elevator frame sections and
securing said clamping inserts against upward and downward movement
relative to said elevator frame sections;
(d) means releasably locking said pipe clamping inserts in assembly
with said elevator frame sections;
(e) lock receiver means defined by said elevator frame
sections;
(f) lock receptacle means defined by each of said pipe clamping
inserts; and
(g) lock elements received in secured relation with said lock
receiver means and establishing engaged relation with said lock
receptacle means so as to secure said pipe clamping inserts against
rotational movement relative to said elevator frame sections.
13. The elevator mechanism of claim 12 wherein:
(a) said pipe clamping inserts each defining an outwardly
projecting upper flange defining at least one lock receptacle
recess opening externally thereof; and
(b) said lock elements being screws received by said frame sections
and engaging within said lock receptacle means.
14. An elevator mechanism for use on drilling rigs for hoisting and
lowering pipe, comprising:
(a) at least two elevator frame sections being interconnected in
relative moveable relation for movement between an open position to
permit assembly thereof about a section of pipe and a closed
position clamping about a section of pipe in preparation for
hoisting and lowering thereof;
(b) at least two pipe clamping inserts being retained in releasable
assembly by respective elevator frame sections and being of a
configuration for interfitting relation with a particular size and
type of pipe,
(c) said elevator frame sections each defining arcuate rims
projecting upwardly from respective elevator frame sections;
and
(d) said pipe clamping inserts defining arcuate retainer means
overlying said arcuate rims and defining downwardly facing arcuate
grooves receiving said arcuate rims therein and restraining
downward axial movement of said pipe clamping inserts relative to
said elevator frame sections.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to elevator systems that are
utilized on well drilling rigs for hoisting and lowering various
types of pipe such as drill stem, well casing and well tubing. More
specifically, the present invention concerns the provision of a
drilling rig elevator assembly having replaceable pipe support
inserts that enable a single elevator frame assembly to be
selectively adapted for hoisting various types and sizes of pipe
during well drilling and completion activities.
2. Description of the Prior Art
In the drilling industry, it is the usual practice to hoist various
types of pipe such as drill stem, well casing and well production
tubing with various elevators of different capacities. The internal
diameters and configurations of the elevators are specifically
dressed for precise interfitting relation with the tool joints of
the pipes to be handled. Under normal well drilling and completion
operations, it is therefore necessary to maintain readily available
to the working floor of the drilling rig a wide selection of
elevators with different capacities and diameters so that the
various types and sizes of pipe and casing may be handled as needed
during various phases of the well drilling and completion
operations.
As drilling rig elevators are designed for carrying substantial
loads, the operating personnel of a drilling rig must carefully
select specific elevators that are intended for a particular
function or purpose. A wide selection of elevators must therefore
typically be maintained in the immediate vicinity of the working
floor of the drilling rig and must be periodically changed out in
order to provide for the handling the different types and sizes of
pipe that are to be used. Obviously, the need for changing out
elevators each time there is a change in the type of pipe or casing
to be handled becomes a significant expense that detracts from the
commercial viability of the drilling operations from the standpoint
of both equipment cost and lost productivity. For lowering or
hoisting pipe of different sizes, elevators must be exchanged i.e.,
actual drilling time is reduced by this elevator exchange
operation. Accordingly, it is desirable to provide a novel drilling
rig elevator assembly having the capability for simple and
efficient low cost conversion thereof to permit its selective
handling of the various types and sizes of pipe, casing and tubing
that are to be handled during well drilling and completion
operations.
It is therefore a principal feature of the present invention to
provide a novel drilling rig elevator system that may be readily
adapted without replacement so that it will receive and efficiently
handle all of the types and sizes of pipe and casing that are
hoisted and lowered during well drilling and completion
operations.
It is another feature of this invention to provide a novel elevator
system for drilling rigs wherein a single elevator frame may be
employed and wherein elevator inserts may be selectively utilized
to adapt the elevator frame for hoisting and lowering any
particular size or type of pipe that is to be handled.
It is an even further feature of the present invention to provide a
novel elevator system for well drilling operations wherein a
moveably joined elevator frame assembly is provided which defines
frame sections having internal insert receptacles and wherein
various types of pipe clamping inserts are selectively disposed in
interlocking and yet easily removable assembly with the respective
elevator frame sections to permit simple and efficient replacement
of elevator inserts without involving significant capital equipment
expense, manual labor costs or drilling rig downtime.
SUMMARY OF THE INVENTION
The various objects and features of the present invention, as set
forth above are realized according to the spirit and scope of the
invention through the provision of an elevator system having
replaceable clamping inserts that selectively adapt the elevator
assembly for handling a particular size and type of pipe and which
can be simply and efficiently converted by insert interchange to
adapt the elevator system for hoisting a different size or type of
pipe. There is provided an elevator frame having a pair of frame
sections that are pivotally interconnected in conventional manner
and are provided with a conventional latch mechanism for securing
the elevator frames in the closed positions thereof Internal
surfaces of each of the elevator frame sections are machined or
otherwise dressed to define internal clamping insert receptacles
which are of arcuate configuration and which establish undercut
regions or other interlocking receptacle geometry. A pair of
clamping inserts are provided for each differing pipe dimension or
configuration so that each pair of replaceable inserts will adapt
the elevator system to hoist and lower a pipe of particular size
and character. Each of the inserts is configured externally for its
precise interfitting assembly with the respective elevator frame
section. Each of the clamping inserts is also externally configured
to define a segment of a circle and defines external interlocking
sections in the form of flanges having a configuration
corresponding of to the configuration of the respective locking
receptacles. These insert segments are installed in interlocked
assembly with the respective elevator frame sections by first
inserting in portions of the interlocking flanges of the clamping
inserts into respective circular insert receptacles or about
circular insert retaining projections and by then rotating the
insert until it is fully received in interlocking relation with the
respective elevator frame section. After the clamping inserts have
been so positioned with respect to each elevator frame sections,
locking elements such as bolts, cap screws, set screws or the like
are then utilized to secure each of the clamping inserts in
immovable, i.e. nonrotatable, relation with respect to the frame
section with which it is assembled.
When it is desirable to replace the clamping inserts of the
elevator frame sections and thereby convert the elevator assembly
for handling another type or size of pipe, the locking elements are
simply released so as to loosen the inserts with respect to the
frame sections. Thereafter, the inserts are simply rotated relative
to the respective frame section so that each insert section will
slide out of its interlocking relationship with the internal
mounting geometry of the frame section. After this has been done, a
replacement clamping insert system having two pipe clamping insert
sections may be caused to slide into interlocking relationship with
the respective frame sections so that, when properly positioned,
the replacement inserts are locked in immovable but replaceable
assembly with the respective elevator frame sections.
BRIEF DESCRIPTION OF THE DRAWINGS
The various objects and advantages of this invention will become
apparent to those skilled in the art upon an understanding of the
following detailed description of the invention, read in light of
the accompanying drawings which are made a part of this
specification and in which:
FIG. 1 is a plan view of a drilling rig elevator assembly having a
pair of frame sections that are shown pivoted to the open condition
thereof and further showing a clamping insert being rotatably moved
as shown by a motion arrow for rotatably sliding it into
interlocking assembly with its frame section.
FIG. 2 is an elevational view of the drilling rig elevator assembly
of FIG. 1 showing the elevator assembly in its closed and latched
condition and with both clamping inserts fully assembled and locked
immovably with respect to individual elevator frame sections.
FIG. 3 is an elevational view of the elevator assembly of FIG. 2
with an internal portion thereof broken away and shown in section
and further showing replaceable clamping inserts being secured in
interlocked assembly therewith, the clamping inserts being
internally profiled for hoisting and lowering of pipe of a
particular type and dimension.
FIG. 4 is an exploded fragmentary sectional view of the upper
portion of the drilling rig elevator and clamping insert assembly
of FIG. 3 for illustrating the manner by which the clamping inserts
are secured in immovable relation with respective frame
sections.
FIG. 5 is a fragmentary sectional view of a lower portion of the
drilling rig elevator and replaceable insert assembly of FIG. 3 and
showing an example of the interlocking relationship that is
established between the elevator frames and clamping inserts.
FIG. 6 is an elevational view of a drilling rig elevator assembly
constructed in accordance with the present invention and having a
central portion thereof broken away and shown in section for
illustration of an alternative embodiment for interlocking
connection of clamping inserts therein, the clamping inserts having
a particular internal profile and dimension for hoisting and
lowering pipe of a particular type and dimension.
FIG. 7 is a fragmentary sectional view of the drilling rig elevator
assembly of FIG. 6 showing an interlocking receptacle and
interlocking flange being disposed in interengaging relation.
FIG. 8 is an elevational view of an elevator assembly representing
a further alternative embodiment of this invention and showing
differing interlocking assembly of a clamping insert therewith, the
clamping insert being internally profiled for a particular type and
dimension of pipe to be hoisted and lowered by the elevator
assembly.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
Referring now the drawings and first to FIGS. 1-3, an elevator
mechanism for use on drilling rigs for hoisting and lowering
various types and sizes of pipe is shown generally at 10 and
incorporates a pair of elevator frame sections 12 and 14 that are
movably interconnected by means of a pivot assembly 16. As is more
evident from FIG. 3, each of the frame sections defines support
means that enable the elevator to be supported by the elevator
links of a conventional drilling rig hoist mechanism. As shown in
FIG. 3, the elevator frame section 12 defines upper and lower
vertically spaced arms 18 and 20 that define respective connection
flanges 22 and 24. These flanges define apertures 26 and 28
respectively, that receive bolts or other suitable connector
elements which secure the upper and lower ends of an elevator
retainer element to the frame section in a manner closing the
elevator link opening 30 that is defined by the spaced arms 18 and
20. The opposite elevator frame section 14 is also provided with
support arms 32 and 34 defining a space 36 therebetween and
providing retainer connector flanges 38 and 40 which receive
another elevator link retainer, not shown. With the elevator link
retainers removed, the lower loops of a pair of elevator links are
positioned within the respective openings or receptacles 30 and 36
with portions of the support loops surrounding the respective upper
arms 18 and 32 of the elevator frame sections. After this has been
done, the elevator link retainers are then assembled to the
respective retainer flanges and are secured by bolts or pins or any
other suitable connectors to close the outer portions of the
openings and secure the elevator links in movably connected and
supporting relation with respective elevator frame sections.
Although a center latch type elevator mechanism is shown in FIGS.
1-3, it should be understood that this embodiment is only intended
to identify the scope of this invention. Other types of elevator
mechanisms, such as side door elevators for example, may also be
manufactured in accordance with the spirit and scope of the present
invention.
In the case of manually operated elevator mechanisms such as shown
in FIGS. 1-3, the elevator frames 12 and 14 may be provided with
respective actuator arms 42 and 44, each having actuator handles 46
and 48, respectively. The frame sections are also provided with an
appropriate latch mechanism so that, when pivoted to the closed
position for clamping about pipe to be hoisted or lowered, the
elevator mechanism will remain latched until such time as it is
controllably unlatched and opened. As shown particularly in FIGS. 1
and 2, elevator frame section 12 is provided with a latch element
50 which is movably connected by a pivot 52 to the actuating arm 42
of the frame section. The latch element 50 is provided with a
movable latch and latch release element 54 that is pivotally
connected thereto by means of a pivot 56. The opposite frame
section 14 is also provided with a latch element 58 which, when the
elevator frames are closed about a pipe, will be received in
interengaging locked relation with respect to latch 50, to thereby
secure the elevator frames in the closed position about the pipe.
When it is desired to release the pipe, the latch mechanism may be
manually actuated to unlatch, after which the actuator arms 42 and
44 may be pivoted apart thereby moving the frames about the pivot
16 from the closed position shown in FIG. 2 to the open position
shown in FIG. 1. The basic elevator frame structure described above
is of conventional nature. As is typically the case, each of the
elevator frame sections will be dressed to receive pipe of a
particular size and geometry. Thus, if pipe of a different size or
geometry is to be hoisted and lowered by the elevator mechanism,
the elevator links must be disconnected from the elevator assembly
and another elevator assembly must be interchanged with it so as to
adapt the hoisting system of the drilling rig for suitably hoisting
and lowering that particular type of pipe. Thus, if the drilling
rig is intended to hoist and lower 2, 3 or 4 different types of
pipe, for example, drill pipe, well casing, well tubing, etc., then
2, 3 or 4 different types of elevators must be readily available at
all times so that they may be changed out and used as needed. When
a pipe change is necessary, the drilling rig will experience
downtime of the hoisting apparatus sufficiently to disconnect the
elevator links from the elevator mechanism being used and reconnect
them to another elevator. Thus, elevator downtime adds
significantly to the overall costs of the drilling operation.
Further, the need for maintaining several elevator assemblies
immediately available to the drilling rig floor results in a
considerable capital expense which adversely effects the cost of
the drilling operation. Therefore, it is desirable to provide a
pipe hoisting elevator mechanism that may be simply and efficiently
converted from one type of pipe to another to thereby minimize
capital expense of the drilling equipment and to also minimize
drilling rig downtime that ordinarily occurs during elevator
interchange.
According to the principles of the present invention, the various
objects and features identified hereinabove are realized through
the provision of an elevator mechanism for drilling rigs that is
adapted for receiving various types of elevator inserts that
quickly and efficiently adapt an elevator assembly for hoisting and
lowering a particular type or size of pipe. As shown in FIGS. 1-3,
the elevator frame sections 12 and 14 are each provided with
essentially semi-circular or arcuate insert receptacles shown
generally at 60 and 62. These receptacles are adapted to receive
generally arcuate insert segments 64 and 66 which are each
appropriately internally dressed for establishing precise
interfitting relation with the geometric configuration of the type
and size of pipe to be hoisted and lowered.
In the preferred embodiment as shown in FIG. 3, the insert
receptacles 60 and 62 are internally dressed to the geometric
configuration shown. The internal wall surface of each receptacle
segment defines a generally cylindrical upper portion 68, a
frusto-conical intermediate section 70 and a generally cylindrical
lower section 72. To provide for interengaging support and
retention of the insert segments 64 and 66, the respective elevator
frame sections 12 and 14 define upwardly projecting retainer
flanges 74 and 76, one of which being shown in greater detail in
FIG. 4. In corresponding fashion, the upper ends of the inserts 64
and 66 define respective retainer flanges 78 and 80 that are
machined to define undercut retainer grooves such as shown at 82 in
FIG. 4. When the insert segments are properly seated with respect
to the frame sections, the upwardly projecting retainer flange
sections or rims will be received within the undercut grooves in
the manner shown in FIG. 4. After this interengaging relationship
has been established, it is then desirable to lock the insert
segments in immovable relation with respect to frame sections. This
is accomplished by providing the upper flanges 78 and 80 of the
insert segments with peripheral locking recesses such as shown at
84 in FIG. 4 and by drilling and tapping holes in the frame
sections as shown at 86. Cap screws 88 are then threaded into the
holes, with the respective heads 90 of the cap screws located
within the peripheral locking recesses 84. With the cap screws so
positioned, the respective insert segments cannot be rotated
relative to the respective frame members and therefore the pipe
clamping inserts will remain in interlocked assembly with the frame
sections and within the respective insert receptacles.
The lower internal portions of each of the frame sections 12 and 14
will be machined to define undercut grooves 92 and 94, a portion of
internal locking groove 92 being shown in the enlarged fragmentary
sectional view of FIG. 5. The circular locking grooves 92 and 94
define circular undercut groove segments such as shown at 96 in
FIG. 5, within which are received hook-like retainer segments 98
projecting upwardly from a retainer flange 100 that extends
radially outwardly from the lower end of each of the insert
segments. Thus, with the inserts in assembly with the respective
frame sections as shown in FIGS. 3, 4 and 5, the inserts are locked
against both downward and upward separating movement. They can only
move to the extent permitted by the tolerances of the respective
upper and lower locking flange engagement of the inserts with
respect to the internal receptacles of the frame sections. Such
tolerances of the inserts are provided such that the insert is
loose enough to slide in the elevator but tight enough so as not to
slip out of the elevator. Finally, the insert segments are dressed
internally by internal surface segments 102, 104, and 106 that are
of a configuration and dimension to receive a pipe collar in close
fitting, clamping relation therebetween when the elevator mechanism
is closed as shown in FIG. 2.
An alternative embodiment of the present invention is shown
generally at 110 in FIGS. 6 and 7 and incorporates elevator frame
sections 112 and 114 that externally are of the same purpose and
configuration as discussed above in connection with FIGS. 1-3.
These frame sections cooperate to define an internal locking
receptacle shown generally at 116 having internal surface segments
118, 120 and 122 essentially corresponding to the internal
receptacle configuration 60 that is shown in FIG. 3 and defined by
surface segments 68, 70 and 72.
The upper portions of the frame sections define upwardly projecting
circular locking segments 124 and 126 which are of the same
structure and function as shown at 74 and 76 in FIG. 3. Within the
lower portions of the each of frame sections, the respective
locking receptacles define internal cylindrical surfaces 128 and
130 that intersect with respective internal cylindrical surfaces
122 and 123 by means of upwardly and outwardly inclined surface
segments 132 and 134. These surface segments in essence define an
undercut insert locking shoulder. The respective replaceable
inserts 136 and 138 each define an upper geometry of the same
configuration and function as described above in connection with
FIGS. 1-3. At the lower portions thereof, the inserts define
outwardly projecting shoulder sections 142 and 144 having upwardly
directed inclined shoulders 146 and 148 that correspond with the
configuration of the undercut inclined shoulder surfaces 132 and
134. The manner by which the inserts 136 and 138 are assembled to
their respective frame sections is by rotatable interconnection
such as shown by the movement arrow in FIG. 1. The inserts are
simply rotated within the insert receptacles of the frame sections
to slide the respective retainer flanges in interengaging relation
with the retainer grooves of the elevator sections until their
respective locking recesses are in alinement with the threaded
holes, such as is shown at 86 in FIG. 1. Thereafter, cap screws 150
are threaded into the locking openings of the frame sections so
that the heads thereof are received in locking relation within the
respective peripheral recesses 152 of the upper locking flange of
each of the inserts.
Typically, the force that is applied to the inserts by pipe is a
downwardly directed force which is resisted by the internal
shoulder 120 of the insert receptacle which provides support for
the external tapered shoulder 154 of the inserts. In the event an
upwardly directed force is applied to the insert segments, the
lower peripheral flange or shoulder 142 and 144 of the insert
segments will secure the insert segments against upward movement.
Obviously, in the case of drilling rig hoist apparatus, the
downwardly directed force that must be accommodated by the elevator
system will significantly exceed any upwardly directed force that
it will experience.
A further alternative embodiment of the present invention is shown
generally at 160 which is in the form of a side door type drilling
rig elevator having a single frame section 162 defining elevator
link support arms 164 and 166 and lower elevator retainer arms 168
and 170 that are disposed in spaced relation with the respective
elevator support arms and define elevator link receptacles 172 and
174. These receptacles are closed by appropriate retaining elements
that are secured thereto by pins or bolts that extend through the
respective apertures thereof in the manner described above. The
elevator frame 162 will be provided with a pivotally mounted side
door type elevator door segment which provides closure for the
elevator about a pipe section when the elevator door segment is
closed and latched. The elevator frame 162 further defines an
internal insert receptacle 176 which is adapted to receive a pipe
support insert 178 in mechanically interengaged and locked relation
therein. The upper portion of the frame segment 162 defines an
upwardly projecting arcuate retainer rim 180 which is of
essentially the same configuration and purpose as is discussed
above at 124-126 in FIG. 6, for receiving the upper externally
flanged end 182 of the insert segment. The undercut receptacle 184
that receives the retainer rim is of corresponding arcuate
configuration so as to permit interlocking engagement of the upper
portion of the frame and insert by moving the arcuate insert in
rotary fashion as is shown by the movement arrow in FIG. 1 until
the insert segment has been received in fully engaged and properly
positioned relation with its frame section. Also for interlocking
interengagement of the lower portion of the insert within the
insert receptacle of the elevator frame, the elevator frame is
internally machined to define a semi-dovetail groove 186 of arcuate
configuration and having an upper upwardly and outwardly inclined
frusto-conical surface 188 which defines a downwardly facing
support shoulder. Correspondingly, the lower end of the pipe
support insert segment 178 is provided with an external locking
flange 190 having an upwardly facing frusto-conical surface 192
which prevents upward movement of the insert segment relative of
the internal insert receptacle of the elevator frame section. For
supporting the insert segment within its receptacle when
significant downward load is applied thereto, the frame section
defines an internally projecting bottom flange 194 of significant
structural integrity which defines an upwardly facing internal
shoulder 196 which is disposed for supporting engagement with the
downwardly facing lower end 198 of the insert segment. The large
circular surface dimension of the shoulder surface 196 provides for
even distribution of load from the pipe support insert to the
elevator frame. The bottom flange also defines a cylindrical
surface 200 defining the central pipe transit opening of the
elevator frame.
For assembly of the insert segment 178 to the frame section an
arcuate end of the insert is positioned so that the flanges 182 and
190 are oriented as shown in FIG. 8 with respect to the arcuate rim
180 and the arcuate retainer groove. Thereafter the insert is
simply rotated until its interlocking flange is fully interengaged
within the corresponding locking groove of its receptacle. The
insert segment is then locked in place by cap screw type retainers
202 that are received within peripheral locking recesses 204 of the
insert flange 182.
In view of the foregoing, it is evident that the present invention
is one well adapted to attain all the objects and features
hereinabove set forth, together with other objects and features
which are inherent in the apparatus disclosed herein.
As will be readily apparent to those skilled in the art, the
present invention may be produced in other specific forms without
departing from its spirit or essential characteristics. The present
embodiment, is therefore, to be considered as illustrative and not
restrictive, the scope of the invention being indicated by the
claims rather than the foregoing description, and all changes which
come within the meaning and range of the equivalence of the claims
are therefore intended to be embraced therein.
* * * * *